<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style type="text/css">
        html, body {
            margin: 0;
            height: 100%;
        }

        canvas {
            display: block;
        }

    </style>
</head>
<body onload="draw();">

</body>
<script src="http://www.yanhuangxueyuan.com/versions/threejsR92/build/three.js"></script>
<script src="js/controls/OrbitControls.js"></script>
<script src="js/libs/stats.min.js"></script>
<script src="js/libs/dat.gui.min.js"></script>
<script>
    var renderer;
    function initRender() {
        renderer = new THREE.WebGLRenderer({antialias: true});
        renderer.setSize(window.innerWidth, window.innerHeight);
        //告诉渲染器需要阴影效果
        renderer.shadowMap.enabled = true;
        renderer.shadowMap.type = THREE.PCFSoftShadowMap; // 默认的是，没有设置的这个清晰 THREE.PCFShadowMap
        document.body.appendChild(renderer.domElement);
    }

    var camera;
    function initCamera() {
        camera = new THREE.PerspectiveCamera(45, window.innerWidth / window.innerHeight, 0.1, 1000);
        camera.position.set(0, 40, 100);
        camera.lookAt(new THREE.Vector3(0, 0, 0));
    }

    var scene;
    function initScene() {
        scene = new THREE.Scene();
    }

    //初始化dat.GUI简化试验流程
    var gui;
    function initGui() {
        //声明一个保存需求修改的相关数据的对象
        gui = {
            lightY: 30, //灯光y轴的位置
            cubeX: 25, //立方体的x轴位置
            cubeY: 10, //立方体的x轴位置
            cubeZ: -5 //立方体的z轴的位置
        };
        var datGui = new dat.GUI();
        //将设置属性添加到gui当中，gui.add(对象，属性，最小值，最大值）
        datGui.add(gui, "lightY", 0, 100);
        datGui.add(gui, "cubeX", -30, 30);
        datGui.add(gui, "cubeY", -30, 30);
        datGui.add(gui, "cubeZ", -30, 30);
    }

    var light;
    function initLight() {
        scene.add(new THREE.AmbientLight(0x444444));

        light = new THREE.PointLight(0xffffff);
        light.position.set(15, 30, 10);

        //告诉平行光需要开启阴影投射
        light.castShadow = true;

        scene.add(light);
    }

    var cube;
    function initModel() {

        //辅助工具
        var helper = new THREE.AxisHelper(10);
        scene.add(helper);

        // 创建一个立方体
        //    v6----- v5
        //   /|      /|
        //  v1------v0|
        //  | |     | |
        //  | |v7---|-|v4
        //  |/      |/
        //  v2------v3

        //立方体
        var cubeGeometry = new THREE.Geometry();

        //创建立方体的顶点
        var vertices = [
            new THREE.Vector3(10, 10, 10), //v0
            new THREE.Vector3(-10, 10, 10), //v1
            new THREE.Vector3(-10, -10, 10), //v2
            new THREE.Vector3(10, -10, 10), //v3
            new THREE.Vector3(10, -10, -10), //v4
            new THREE.Vector3(10, 10, -10), //v5
            new THREE.Vector3(-10, 10, -10), //v6
            new THREE.Vector3(-10, -10, -10) //v7
        ];

        cubeGeometry.vertices = vertices;

        //创建立方的面
        var faces=[
            new THREE.Face3(0,1,2),
            new THREE.Face3(0,2,3),
            new THREE.Face3(0,3,4),
            new THREE.Face3(0,4,5),
            new THREE.Face3(1,6,7),
            new THREE.Face3(1,7,2),
            new THREE.Face3(6,5,4),
            new THREE.Face3(6,4,7),
            new THREE.Face3(5,6,1),
            new THREE.Face3(5,1,0),
            new THREE.Face3(3,2,7),
            new THREE.Face3(3,7,4)
        ];

        cubeGeometry.faces = faces;

        //生成法向量
        cubeGeometry.computeFaceNormals();

        var cubeMaterial = new THREE.MeshLambertMaterial({color: 0x00ffff});

        cube = new THREE.Mesh(cubeGeometry, cubeMaterial);
        cube.position.x = 25;
        cube.position.y = 5;
        cube.position.z = -5;

        //告诉立方体需要投射阴影
        cube.castShadow = true;

        scene.add(cube);

        //底部平面
        var planeGeometry = new THREE.PlaneGeometry(100, 100);
        var planeMaterial = new THREE.MeshLambertMaterial({color: 0xaaaaaa});

        var plane = new THREE.Mesh(planeGeometry, planeMaterial);
        plane.rotation.x = -0.5 * Math.PI;
        plane.position.y = -0;

        //告诉底部平面需要接收阴影
        plane.receiveShadow = true;

        scene.add(plane);

    }

    //初始化性能插件
    var stats;
    function initStats() {
        stats = new Stats();
        document.body.appendChild(stats.dom);
    }

    //用户交互插件 鼠标左键按住旋转，右键按住平移，滚轮缩放
    var controls;
    function initControls() {

        controls = new THREE.OrbitControls(camera, renderer.domElement);

        // 如果使用animate方法时，将此函数删除
        //controls.addEventListener( 'change', render );
        // 使动画循环使用时阻尼或自转 意思是否有惯性
        controls.enableDamping = true;
        //动态阻尼系数 就是鼠标拖拽旋转灵敏度
        //controls.dampingFactor = 0.25;
        //是否可以缩放
        controls.enableZoom = true;
        //是否自动旋转
        controls.autoRotate = false;
        //设置相机距离原点的最远距离
        controls.minDistance = 50;
        //设置相机距离原点的最远距离
        controls.maxDistance = 200;
        //是否开启右键拖拽
        controls.enablePan = true;
    }

    function render() {
        renderer.render(scene, camera);
    }

    //窗口变动触发的函数
    function onWindowResize() {

        camera.aspect = window.innerWidth / window.innerHeight;
        camera.updateProjectionMatrix();
        render();
        renderer.setSize(window.innerWidth, window.innerHeight);

    }

    function animate() {
        //更新控制器
        render();

        //更新性能插件
        stats.update();

        //更新相关位置
        light.position.y = gui.lightY;
        cube.position.x = gui.cubeX;
        cube.position.y = gui.cubeY;
        cube.position.z = gui.cubeZ;

        controls.update();

        requestAnimationFrame(animate);
    }

    function draw() {
        initGui();
        initRender();
        initScene();
        initCamera();
        initLight();
        initModel();
        initControls();
        initStats();

        animate();
        window.onresize = onWindowResize;
    }
</script>
</html>